QuickBooks Online is an awesome all-in-one solution for your business bookkeeping. Entering products and services is a simple and straightforward process, and I want to make sure you're able to select them without issues when creating invoices. I'd be happy to go through some troubleshooting steps you can try to get this sorted out.
It sounds like you may be experiencing a browser-related issue that's causing latency and loading issues in your account. Here's a few steps you can try to resolve this: